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2022-07-03Remove %error-verbose directive from jsonpath parserAndrew Dunstan
None of the other bison parsers contains this directive, and it gives rise to some unfortunate and impenetrable messages, so just remove it. Backpatch to release 12, where it was introduced. Per gripe from Erik Rijkers Discussion: https://postgr.es/m/ba069ce2-a98f-dc70-dc17-2ccf2a9bf7c7@xs4all.nl
2022-06-27Fix visibility check when XID is committed in CLOG but not in procarray.Heikki Linnakangas
TransactionIdIsInProgress had a fast path to return 'false' if the single-item CLOG cache said that the transaction was known to be committed. However, that was wrong, because a transaction is first marked as committed in the CLOG but doesn't become visible to others until it has removed its XID from the proc array. That could lead to an error: ERROR: t_xmin is uncommitted in tuple to be updated or for an UPDATE to go ahead without blocking, before the previous UPDATE on the same row was made visible. The window is usually very short, but synchronous replication makes it much wider, because the wait for synchronous replica happens in that window. Another thing that makes it hard to hit is that it's hard to get such a commit-in-progress transaction into the single item CLOG cache. Normally, if you call TransactionIdIsInProgress on such a transaction, it determines that the XID is in progress without checking the CLOG and without populating the cache. One way to prime the cache is to explicitly call pg_xact_status() on the XID. Another way is to use a lot of subtransactions, so that the subxid cache in the proc array is overflown, making TransactionIdIsInProgress rely on pg_subtrans and CLOG checks. This has been broken ever since it was introduced in 2008, but the race condition is very hard to hit, especially without synchronous replication. There were a couple of reports of the error starting from summer 2021, but no one was able to find the root cause then. TransactionIdIsKnownCompleted() is now unused. In 'master', remove it, but I left it in place in backbranches in case it's used by extensions. Also change pg_xact_status() to check TransactionIdIsInProgress(). Previously, it only checked the CLOG, and returned "committed" before the transaction was actually made visible to other queries. Note that this also means that you cannot use pg_xact_status() to reproduce the bug anymore, even if the code wasn't fixed. Report and analysis by Konstantin Knizhnik. Patch by Simon Riggs, with the pg_xact_status() change added by me. Author: Simon Riggs Reviewed-by: Andres Freund Discussion: https://www.postgresql.org/message-id/flat/4da7913d-398c-e2ad-d777-f752cf7f0bbb%40garret.ru
2022-06-22Fix SPI's handling of errors during transaction commit.Tom Lane
SPI_commit previously left it up to the caller to recover from any error occurring during commit. Since that's complicated and requires use of low-level xact.c facilities, it's not too surprising that no caller got it right. Let's move the responsibility for cleanup into spi.c. Doing that requires redefining SPI_commit as starting a new transaction, so that it becomes equivalent to SPI_commit_and_chain except that you get default transaction characteristics instead of preserving the prior transaction's characteristics. We can make this pretty transparent API-wise by redefining SPI_start_transaction() as a no-op. Callers that expect to do something in between might be surprised, but available evidence is that no callers do so. Having made that API redefinition, we can fix this mess by having SPI_commit[_and_chain] trap errors and start a new, clean transaction before re-throwing the error. Likewise for SPI_rollback[_and_chain]. Some cleanup is also needed in AtEOXact_SPI, which was nowhere near smart enough to deal with SPI contexts nested inside a committing context. While plperl and pltcl need no changes beyond removing their now-useless SPI_start_transaction() calls, plpython needs some more work because it hadn't gotten the memo about catching commit/rollback errors in the first place. Such an error resulted in longjmp'ing out of the Python interpreter, which leaks Python stack entries at present and is reported to crash Python 3.11 altogether. Add the missing logic to catch such errors and convert them into Python exceptions. This is a back-patch of commit 2e517818f. That's now aged long enough to reduce the concerns about whether it will break something, and we do need to ensure that supported branches will work with Python 3.11. Peter Eisentraut and Tom Lane Discussion: https://postgr.es/m/3375ffd8-d71c-2565-e348-a597d6e739e3@enterprisedb.com Discussion: https://postgr.es/m/17416-ed8fe5d7213d6c25@postgresql.org
2022-05-31Ensure ParseTzFile() closes the input file after failing.Tom Lane
We hadn't noticed this because (a) few people feed invalid timezone abbreviation files to the server, and (b) in typical scenarios guc.c would throw ereport(ERROR) and then transaction abort handling would silently clean up the leaked file reference. However, it was possible to observe file leakage warnings if one breaks an already-active abbreviation file, because guc.c does not throw ERROR when loading supposedly-validated settings during session start or SIGHUP processing. Report and fix by Kyotaro Horiguchi (cosmetic adjustments by me) Discussion: https://postgr.es/m/20220530.173740.748502979257582392.horikyota.ntt@gmail.com
2022-05-28Handle NULL for short descriptions of custom GUC variablesMichael Paquier
If a short description is specified as NULL in one of the various DefineCustomXXXVariable() functions available to external modules to define a custom parameter, SHOW ALL would crash. This change teaches SHOW ALL to properly handle NULL short descriptions, as well as any code paths that manipulate it, to gain in flexibility. Note that help_config.c was already able to do that, when describing a set of GUCs for postgres --describe-config. Author: Steve Chavez Reviewed by: Nathan Bossart, Andres Freund, Michael Paquier, Tom Lane Discussion: https://postgr.es/m/CAGRrpzY6hO-Kmykna_XvsTv8P2DshGiU6G3j8yGao4mk0CqjHA%40mail.gmail.com Backpatch-through: 10
2022-05-21Show 'AS "?column?"' explicitly when it's important.Tom Lane
ruleutils.c was coded to suppress the AS label for a SELECT output expression if the column name is "?column?", which is the parser's fallback if it can't think of something better. This is fine, and avoids ugly clutter, so long as (1) nothing further up in the parse tree relies on that column name or (2) the same fallback would be assigned when the rule or view definition is reloaded. Unfortunately (2) is far from certain, both because ruleutils.c might print the expression in a different form from how it was originally written and because FigureColname's rules might change in future releases. So we shouldn't rely on that. Detecting exactly whether there is any outer-level use of a SELECT column name would be rather expensive. This patch takes the simpler approach of just passing down a flag indicating whether there *could* be any outer use; for example, the output column names of a SubLink are not referenceable, and we also do not care about the names exposed by the right-hand side of a setop. This is sufficient to suppress unwanted clutter in all but one case in the regression tests. That seems like reasonable evidence that it won't be too much in users' faces, while still fixing the cases we need to fix. Per bug #17486 from Nicolas Lutic. This issue is ancient, so back-patch to all supported branches. Discussion: https://postgr.es/m/17486-1ad6fd786728b8af@postgresql.org
2022-05-09Revert "Disallow infinite endpoints in generate_series() for timestamps."Tom Lane
This reverts commit eafdf9de06e9b60168f5e47cedcfceecdc6d4b5f and its back-branch counterparts. Corey Huinker pointed out that we'd discussed this exact change back in 2016 and rejected it, on the grounds that there's at least one usage pattern with LIMIT where an infinite endpoint can usefully be used. Perhaps that argument needs to be re-litigated, but there's no time left before our back-branch releases. To keep our options open, restore the status quo ante; if we do end up deciding to change things, waiting one more quarter won't hurt anything. Rather than just doing a straight revert, I added a new test case demonstrating the usage with LIMIT. That'll at least remind us of the issue if we forget again. Discussion: https://postgr.es/m/3603504.1652068977@sss.pgh.pa.us Discussion: https://postgr.es/m/CADkLM=dzw0Pvdqp5yWKxMd+VmNkAMhG=4ku7GnCZxebWnzmz3Q@mail.gmail.com
2022-05-09Make relation-enumerating operations be security-restricted operations.Noah Misch
When a feature enumerates relations and runs functions associated with all found relations, the feature's user shall not need to trust every user having permission to create objects. BRIN-specific functionality in autovacuum neglected to account for this, as did pg_amcheck and CLUSTER. An attacker having permission to create non-temp objects in at least one schema could execute arbitrary SQL functions under the identity of the bootstrap superuser. CREATE INDEX (not a relation-enumerating operation) and REINDEX protected themselves too late. This change extends to the non-enumerating amcheck interface. Back-patch to v10 (all supported versions). Sergey Shinderuk, reviewed (in earlier versions) by Alexander Lakhin. Reported by Alexander Lakhin. Security: CVE-2022-1552
2022-04-20Fix CLUSTER tuplesorts on abbreviated expressions.Peter Geoghegan
CLUSTER sort won't use the datum1 SortTuple field when clustering against an index whose leading key is an expression. This makes it unsafe to use the abbreviated keys optimization, which was missed by the logic that sets up SortSupport state. Affected tuplesorts output tuples in a completely bogus order as a result (the wrong SortSupport based comparator was used for the leading attribute). This issue is similar to the bug fixed on the master branch by recent commit cc58eecc5d. But it's a far older issue, that dates back to the introduction of the abbreviated keys optimization by commit 4ea51cdfe8. Backpatch to all supported versions. Author: Peter Geoghegan <pg@bowt.ie> Author: Thomas Munro <thomas.munro@gmail.com> Discussion: https://postgr.es/m/CA+hUKG+bA+bmwD36_oDxAoLrCwZjVtST2fqe=b4=qZcmU7u89A@mail.gmail.com Backpatch: 10-
2022-04-20Disallow infinite endpoints in generate_series() for timestamps.Tom Lane
Such cases will lead to infinite loops, so they're of no practical value. The numeric variant of generate_series() already threw error for this, so borrow its message wording. Per report from Richard Wesley. Back-patch to all supported branches. Discussion: https://postgr.es/m/91B44E7B-68D5-448F-95C8-B4B3B0F5DEAF@duckdblabs.com
2022-03-23Don't try to translate NULL in GetConfigOptionByNum().Andres Freund
Noticed via -fsanitize=undefined. Introduced when a few columns in GetConfigOptionByNum() / pg_settings started to be translated in 72be8c29a / PG 12. Backpatch to all affected branches, for the same reasons as 46ab07ffda9. Discussion: https://postgr.es/m/20220323173537.ll7klrglnp4gn2um@alap3.anarazel.de Backpatch: 12-
2022-03-23Don't call fwrite() with len == 0 when writing out relcache init file.Andres Freund
Noticed via -fsanitize=undefined. Backpatch to all branches, for the same reasons as 46ab07ffda9. Discussion: https://postgr.es/m/20220323173537.ll7klrglnp4gn2um@alap3.anarazel.de Backpatch: 10-
2022-03-21Fix assorted missing logic for GroupingFunc nodes.Tom Lane
The planner needs to treat GroupingFunc like Aggref for many purposes, in particular with respect to processing of the argument expressions, which are not to be evaluated at runtime. A few places hadn't gotten that memo, notably including subselect.c's processing of outer-level aggregates. This resulted in assertion failures or wrong plans for cases in which a GROUPING() construct references an outer aggregation level. Also fix missing special cases for GroupingFunc in cost_qual_eval (resulting in wrong cost estimates for GROUPING(), although it's not clear that that would affect plan shapes in practice) and in ruleutils.c (resulting in excess parentheses in pretty-print mode). Per bug #17088 from Yaoguang Chen. Back-patch to all supported branches. Richard Guo, Tom Lane Discussion: https://postgr.es/m/17088-e33882b387de7f5c@postgresql.org
2022-03-18Fix incorrect xmlschema output for types timetz and timestamptz.Tom Lane
The output of table_to_xmlschema() and allied functions includes a regex describing valid values for these types ... but the regex was itself invalid, as it failed to escape a literal "+" sign. Report and fix by Renan Soares Lopes. Back-patch to all supported branches. Discussion: https://postgr.es/m/7f6fabaa-3f8f-49ab-89ca-59fbfe633105@me.com
2022-03-03Clean up assorted failures under clang's -fsanitize=undefined checks.Tom Lane
Most of these are cases where we could call memcpy() or other libc functions with a NULL pointer and a zero count, which is forbidden by POSIX even though every production version of libc allows it. We've fixed such things before in a piecemeal way, but apparently never made an effort to try to get them all. I don't claim that this patch does so either, but it gets every failure I observe in check-world, using clang 12.0.1 on current RHEL8. numeric.c has a different issue that the sanitizer doesn't like: "ln(-1.0)" will compute log10(0) and then try to assign the resulting -Inf to an integer variable. We don't actually use the result in such a case, so there's no live bug. Back-patch to all supported branches, with the idea that we might start running a buildfarm member that tests this case. This includes back-patching c1132aae3 (Check the size in COPY_POINTER_FIELD), which previously silenced some of these issues in copyfuncs.c. Discussion: https://postgr.es/m/CALNJ-vT9r0DSsAOw9OXVJFxLENoVS_68kJ5x0p44atoYH+H4dg@mail.gmail.com
2022-02-17Suppress warning about stack_base_ptr with late-model GCC.Tom Lane
GCC 12 complains that set_stack_base is storing the address of a local variable in a long-lived pointer. This is an entirely reasonable warning (indeed, it just helped us find a bug); but that behavior is intentional here. We can work around it by using __builtin_frame_address(0) instead of a specific local variable; that produces an address a dozen or so bytes different, in my testing, but we don't care about such a small difference. Maybe someday a compiler lacking that function will start to issue a similar warning, but we'll worry about that when it happens. Patch by me, per a suggestion from Andres Freund. Back-patch to v12, which is as far back as the patch will go without some pain. (Recently-established project policy would permit a back-patch as far as 9.2, but I'm disinclined to expend the work until GCC 12 is much more widespread.) Discussion: https://postgr.es/m/3773792.1645141467@sss.pgh.pa.us
2022-02-09Fix back-patch of "Avoid race in RelationBuildDesc() ..."Noah Misch
The back-patch of commit fdd965d074d46765c295223b119ca437dbcac973 broke CLOBBER_CACHE_ALWAYS for v9.6 through v13. It updated the InvalidateSystemCaches() call for CLOBBER_CACHE_RECURSIVELY, neglecting the one for CLOBBER_CACHE_ALWAYS. Back-patch to v13, v12, v11, and v10. Reviewed by Tomas Vondra. Reported by Tomas Vondra. Discussion: https://postgr.es/m/df7b4c0b-7d92-f03f-75c4-9e08b269a716@enterprisedb.com
2022-01-27Fix ordering of XIDs in ProcArrayApplyRecoveryInfoTomas Vondra
Commit 8431e296ea reworked ProcArrayApplyRecoveryInfo to sort XIDs before adding them to KnownAssignedXids. But the XIDs are sorted using xidComparator, which compares the XIDs simply as uint32 values, not logically. KnownAssignedXidsAdd() however expects XIDs in logical order, and calls TransactionIdFollowsOrEquals() to enforce that. If there are XIDs for which the two orderings disagree, an error is raised and the recovery fails/restarts. Hitting this issue is fairly easy - you just need two transactions, one started before the 4B limit (e.g. XID 4294967290), the other sometime after it (e.g. XID 1000). Logically (4294967290 <= 1000) but when compared using xidComparator we try to add them in the opposite order. Which makes KnownAssignedXidsAdd() fail with an error like this: ERROR: out-of-order XID insertion in KnownAssignedXids This only happens during replica startup, while processing RUNNING_XACTS records to build the snapshot. Once we reach STANDBY_SNAPSHOT_READY, we skip these records. So this does not affect already running replicas, but if you restart (or create) a replica while there are transactions with XIDs for which the two orderings disagree, you may hit this. Long-running transactions and frequent replica restarts increase the likelihood of hitting this issue. Once the replica gets into this state, it can't be started (even if the old transactions are terminated). Fixed by sorting the XIDs logically - this is fine because we're dealing with normal XIDs (because it's XIDs assigned to backends) and from the same wraparound epoch (otherwise the backends could not be running at the same time on the primary node). So there are no problems with the triangle inequality, which is why xidComparator compares raw values. Investigation and root cause analysis by Abhijit Menon-Sen. Patch by me. This issue is present in all releases since 9.4, however releases up to 9.6 are EOL already so backpatch to 10 only. Reviewed-by: Abhijit Menon-Sen Reviewed-by: Alvaro Herrera Backpatch-through: 10 Discussion: https://postgr.es/m/36b8a501-5d73-277c-4972-f58a4dce088a%40enterprisedb.com
2022-01-15Build inherited extended stats on partitioned tablesTomas Vondra
Commit 859b3003de disabled building of extended stats for inheritance trees, to prevent updating the same catalog row twice. While that resolved the issue, it also means there are no extended stats for declaratively partitioned tables, because there are no data in the non-leaf relations. That also means declaratively partitioned tables were not affected by the issue 859b3003de addressed, which means this is a regression affecting queries that calculate estimates for the whole inheritance tree as a whole (which includes e.g. GROUP BY queries). But because partitioned tables are empty, we can invert the condition and build statistics only for the case with inheritance, without losing anything. And we can consider them when calculating estimates. It may be necessary to run ANALYZE on partitioned tables, to collect proper statistics. For declarative partitioning there should no prior statistics, and it might take time before autoanalyze is triggered. For tables partitioned by inheritance the statistics may include data from child relations (if built 859b3003de), contradicting the current code. Report and patch by Justin Pryzby, minor fixes and cleanup by me. Backpatch all the way back to PostgreSQL 10, where extended statistics were introduced (same as 859b3003de). Author: Justin Pryzby Reported-by: Justin Pryzby Backpatch-through: 10 Discussion: https://postgr.es/m/20210923212624.GI831%40telsasoft.com
2022-01-15Ignore extended statistics for inheritance treesTomas Vondra
Since commit 859b3003de we only build extended statistics for individual relations, ignoring the child relations. This resolved the issue with updating catalog tuple twice, but we still tried to use the statistics when calculating estimates for the whole inheritance tree. When the relations contain very distinct data, it may produce bogus estimates. This is roughly the same issue 427c6b5b9 addressed ~15 years ago, and we fix it the same way - by ignoring extended statistics when calculating estimates for the inheritance tree as a whole. We still consider extended statistics when calculating estimates for individual child relations, of course. This may result in plan changes due to different estimates, but if the old statistics were not describing the inheritance tree particularly well it's quite likely the new plans is actually better. Report and patch by Justin Pryzby, minor fixes and cleanup by me. Backpatch all the way back to PostgreSQL 10, where extended statistics were introduced (same as 859b3003de). Author: Justin Pryzby Reported-by: Justin Pryzby Backpatch-through: 10 Discussion: https://postgr.es/m/20210923212624.GI831%40telsasoft.com
2022-01-13Fix ruleutils.c's dumping of whole-row Vars in more contexts.Tom Lane
Commit 7745bc352 intended to ensure that whole-row Vars would be printed with "::type" decoration in all contexts where plain "var.*" notation would result in star-expansion, notably in ROW() and VALUES() constructs. However, it missed the case of INSERT with a single-row VALUES, as reported by Timur Khanjanov. Nosing around ruleutils.c, I found a second oversight: the code for RowCompareExpr generates ROW() notation without benefit of an actual RowExpr, and naturally it wasn't in sync :-(. (The code for FieldStore also does this, but we don't expect that to generate strictly parsable SQL anyway, so I left it alone.) Back-patch to all supported branches. Discussion: https://postgr.es/m/efaba6f9-4190-56be-8ff2-7a1674f9194f@intrans.baku.az
2021-10-23Fix CREATE INDEX CONCURRENTLY for the newest prepared transactions.Noah Misch
The purpose of commit 8a54e12a38d1545d249f1402f66c8cde2837d97c was to fix this, and it sufficed when the PREPARE TRANSACTION completed before the CIC looked for lock conflicts. Otherwise, things still broke. As before, in a cluster having used CIC while having enabled prepared transactions, queries that use the resulting index can silently fail to find rows. It may be necessary to reindex to recover from past occurrences; REINDEX CONCURRENTLY suffices. Fix this for future index builds by making CIC wait for arbitrarily-recent prepared transactions and for ordinary transactions that may yet PREPARE TRANSACTION. As part of that, have PREPARE TRANSACTION transfer locks to its dummy PGPROC before it calls ProcArrayClearTransaction(). Back-patch to 9.6 (all supported versions). Andrey Borodin, reviewed (in earlier versions) by Andres Freund. Discussion: https://postgr.es/m/01824242-AA92-4FE9-9BA7-AEBAFFEA3D0C@yandex-team.ru
2021-10-23Avoid race in RelationBuildDesc() affecting CREATE INDEX CONCURRENTLY.Noah Misch
CIC and REINDEX CONCURRENTLY assume backends see their catalog changes no later than each backend's next transaction start. That failed to hold when a backend absorbed a relevant invalidation in the middle of running RelationBuildDesc() on the CIC index. Queries that use the resulting index can silently fail to find rows. Fix this for future index builds by making RelationBuildDesc() loop until it finishes without accepting a relevant invalidation. It may be necessary to reindex to recover from past occurrences; REINDEX CONCURRENTLY suffices. Back-patch to 9.6 (all supported versions). Noah Misch and Andrey Borodin, reviewed (in earlier versions) by Andres Freund. Discussion: https://postgr.es/m/20210730022548.GA1940096@gust.leadboat.com
2021-10-06Fix corner-case loss of precision in numeric_power().Dean Rasheed
This fixes a loss of precision that occurs when the first input is very close to 1, so that its logarithm is very small. Formerly, during the initial low-precision calculation to estimate the result weight, the logarithm was computed to a local rscale that was capped to NUMERIC_MAX_DISPLAY_SCALE (1000). However, the base may be as close as 1e-16383 to 1, hence its logarithm may be as small as 1e-16383, and so the local rscale needs to be allowed to exceed 16383, otherwise all precision is lost, leading to a poor choice of rscale for the full-precision calculation. Fix this by removing the cap on the local rscale during the initial low-precision calculation, as we already do in the full-precision calculation. This doesn't change the fact that the initial calculation is a low-precision approximation, computing the logarithm to around 8 significant digits, which is very fast, especially when the base is very close to 1. Patch by me, reviewed by Alvaro Herrera. Discussion: https://postgr.es/m/CAEZATCV-Ceu%2BHpRMf416yUe4KKFv%3DtdgXQAe5-7S9tD%3D5E-T1g%40mail.gmail.com
2021-10-01Avoid believing incomplete MCV-only stats in get_variable_range().Tom Lane
get_variable_range() would incautiously believe that statistics containing only an MCV list are sufficient to derive a range estimate. That's okay for an enum-like column that contains only MCVs, but otherwise the estimate could be pretty bad. Make it report that the range is indeterminate unless the MCVs plus nullfrac account for the whole table. I don't think this needs a dedicated test case, since a quick code coverage check verifies that the existing regression tests traverse all the alternatives. There is room to doubt that a future-proof test case could be built anyway, given that the submitted example accidentally doesn't fail before v11. Per bug #17207 from Simon Perepelitsa. Back-patch to v10. In principle this has been broken all along, but I'm hesitant to make such changes in 9.6, since if anyone is unhappy with 9.6.24's behavior there will be no second chance to fix it. Discussion: https://postgr.es/m/17207-5265aefa79e333b4@postgresql.org
2021-10-01Fix Portal snapshot tracking to handle subtransactions properly.Tom Lane
Commit 84f5c2908 forgot to consider the possibility that EnsurePortalSnapshotExists could run inside a subtransaction with lifespan shorter than the Portal's. In that case, the new active snapshot would be popped at the end of the subtransaction, leaving a dangling pointer in the Portal, with mayhem ensuing. To fix, make sure the ActiveSnapshot stack entry is marked with the same subtransaction nesting level as the associated Portal. It's certainly safe to do so since we won't be here at all unless the stack is empty; hence we can't create an out-of-order stack. Let's also apply this logic in the case where PortalRunUtility sets portalSnapshot, just to be sure that path can't cause similar problems. It's slightly less clear that that path can't create an out-of-order stack, so add an assertion guarding it. Report and patch by Bertrand Drouvot (with kibitzing by me). Back-patch to v11, like the previous commit. Discussion: https://postgr.es/m/ff82b8c5-77f4-3fe7-6028-fcf3303e82dd@amazon.com
2021-09-06Fix bogus timetz_zone() results for DYNTZ abbreviations.Tom Lane
timetz_zone() delivered completely wrong answers if the zone was specified by a dynamic TZ abbreviation, because it failed to account for the difference between the POSIX conventions for field values in struct pg_tm and the conventions used in PG-specific datetime code. As a stopgap fix, just adjust the tm_year and tm_mon fields to match PG conventions. This is fixed in a different way in HEAD (388e71af8) but I don't want to back-patch the change of reference point. Discussion: https://postgr.es/m/CAJ7c6TOMG8zSNEZtCn5SPe+cCk3Lfxb71ZaQwT2F4T7PJ_t=KA@mail.gmail.com
2021-08-25Improve error message about valid value for distance in phrase operator.Fujii Masao
The distance in phrase operator must be an integer value between zero and MAXENTRYPOS inclusive. But previously the error message about its valid value included the information about its upper limit but not lower limit (i.e., zero). This commit improves the error message so that it also includes the information about its lower limit. Back-patch to v9.6 where full-text phrase search was supported. Author: Kyotaro Horiguchi Reviewed-by: Fujii Masao Discussion: https://postgr.es/m/20210819.170315.1413060634876301811.horikyota.ntt@gmail.com
2021-08-06Adjust the integer overflow tests in the numeric code.Dean Rasheed
Formerly, the numeric code tested whether an integer value of a larger type would fit in a smaller type by casting it to the smaller type and then testing if the reverse conversion produced the original value. That's perfectly fine, except that it caused a test failure on buildfarm animal castoroides, most likely due to a compiler bug. Instead, do these tests by comparing against PG_INT16/32_MIN/MAX. That matches existing code in other places, such as int84(), which is more widely tested, and so is less likely to go wrong. While at it, add regression tests covering the numeric-to-int8/4/2 conversions, and adjust the recently added tests to the style of 434ddfb79a (on the v11 branch) to make failures easier to diagnose. Per buildfarm via Tom Lane, reviewed by Tom Lane. Discussion: https://postgr.es/m/2394813.1628179479%40sss.pgh.pa.us
2021-08-06Fix wordingPeter Eisentraut
2021-08-05Fix division-by-zero error in to_char() with 'EEEE' format.Dean Rasheed
This fixes a long-standing bug when using to_char() to format a numeric value in scientific notation -- if the value's exponent is less than -NUMERIC_MAX_DISPLAY_SCALE-1 (-1001), it produced a division-by-zero error. The reason for this error was that get_str_from_var_sci() divides its input by 10^exp, which it produced using power_var_int(). However, the underflow test in power_var_int() causes it to return zero if the result scale is too small. That's not a problem for power_var_int()'s only other caller, power_var(), since that limits the rscale to 1000, but in get_str_from_var_sci() the exponent can be much smaller, requiring a much larger rscale. Fix by introducing a new function to compute 10^exp directly, with no rscale limit. This also allows 10^exp to be computed more efficiently, without any numeric multiplication, division or rounding. Discussion: https://postgr.es/m/CAEZATCWhojfH4whaqgUKBe8D5jNHB8ytzemL-PnRx+KCTyMXmg@mail.gmail.com
2021-07-31Fix corner-case errors and loss of precision in numeric_power().Dean Rasheed
This fixes a couple of related problems that arise when raising numbers to very large powers. Firstly, when raising a negative number to a very large integer power, the result should be well-defined, but the previous code would only cope if the exponent was small enough to go through power_var_int(). Otherwise it would throw an internal error, attempting to take the logarithm of a negative number. Fix this by adding suitable handling to the general case in power_var() to cope with negative bases, checking for integer powers there. Next, when raising a (positive or negative) number whose absolute value is slightly less than 1 to a very large power, the result should approach zero as the power is increased. However, in some cases, for sufficiently large powers, this would lose all precision and return 1 instead of 0. This was due to the way that the local_rscale was being calculated for the final full-precision calculation: local_rscale = rscale + (int) val - ln_dweight + 8 The first two terms on the right hand side are meant to give the number of significant digits required in the result ("val" being the estimated result weight). However, this failed to account for the fact that rscale is clipped to a maximum of NUMERIC_MAX_DISPLAY_SCALE (1000), and the result weight might be less then -1000, causing their sum to be negative, leading to a loss of precision. Fix this by forcing the number of significant digits calculated to be nonnegative. It's OK for it to be zero (when the result weight is less than -1000), since the local_rscale value then includes a few extra digits to ensure an accurate result. Finally, add additional underflow checks to exp_var() and power_var(), so that they consistently return zero for cases like this where the result is indistinguishable from zero. Some paths through this code already returned zero in such cases, but others were throwing overflow errors. Dean Rasheed, reviewed by Yugo Nagata. Discussion: http://postgr.es/m/CAEZATCW6Dvq7+3wN3tt5jLj-FyOcUgT5xNoOqce5=6Su0bCR0w@mail.gmail.com
2021-07-27Set pg_setting.pending_restart when pertinent config lines are removedAlvaro Herrera
This changes the behavior of examining the pg_file_settings view after changing a config option that requires restart. The user needs to know that any change of such options does not take effect until a restart, and this worked correctly if the line is edited without removing it. However, for the case where the line is removed altogether, the flag doesn't get set, because a flag was only set in set_config_option, but that's not called for lines removed. Repair. (Ref.: commits 62d16c7fc561 and a486e35706ea) Author: Álvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Daniel Gustafsson <daniel@yesql.se> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/202107262302.xsfdfc5sb7sh@alvherre.pgsql
2021-07-28Avoid using ambiguous word "non-negative" in error messages.Fujii Masao
The error messages using the word "non-negative" are confusing because it's ambiguous about whether it accepts zero or not. This commit improves those error messages by replacing it with less ambiguous word like "greater than zero" or "greater than or equal to zero". Also this commit added the note about the word "non-negative" to the error message style guide, to help writing the new error messages. When postgres_fdw option fetch_size was set to zero, previously the error message "fetch_size requires a non-negative integer value" was reported. This error message was outright buggy. Therefore back-patch to all supported versions where such buggy error message could be thrown. Reported-by: Hou Zhijie Author: Bharath Rupireddy Reviewed-by: Kyotaro Horiguchi, Fujii Masao Discussion: https://postgr.es/m/OS0PR01MB5716415335A06B489F1B3A8194569@OS0PR01MB5716.jpnprd01.prod.outlook.com
2021-07-21Document "B" and "us" as accepted units in postgres.conf.sampleJohn Naylor
In postgresql.conf, memory and file size GUCs can be specified with "B" (bytes) as of b06d8e58b. Likewise, time GUCs can be specified with "us" (microseconds) as of caf626b2c. Update postgres.conf.sample to reflect that fact. Pavel Luzanov Backpatch to v12, which is the earliest version that allows both of these units. A separate commit will document the "B" case for v11. Discussion: https://www.postgresql.org/message-id/flat/f10d16fc-8fa0-1b3c-7371-cb3a35a13b7a%40postgrespro.ru
2021-07-13Robustify tuplesort's free_sort_tuple functionDavid Rowley
41469253e went to the trouble of removing a theoretical bug from free_sort_tuple by checking if the tuple was NULL before freeing it. Let's make this a little more robust by also setting the tuple to NULL so that should we be called again we won't end up doing a pfree on the already pfree'd tuple. Per advice from Tom Lane. Discussion: https://postgr.es/m/3188192.1626136953@sss.pgh.pa.us Backpatch-through: 9.6, same as 41469253e
2021-07-13Fix theoretical bug in tuplesortDavid Rowley
This fixes a theoretical bug in tuplesort.c which, if a bounded sort was used in combination with a byval Datum sort (tuplesort_begin_datum), when switching the sort to a bounded heap in make_bounded_heap(), we'd call free_sort_tuple(). The problem was that when sorting Datums of a byval type, the tuple is NULL and free_sort_tuple() would free the memory for it regardless of that. This would result in a crash. Here we fix that simply by adding a check to see if the tuple is NULL before trying to disassociate and free any memory belonging to it. The reason this bug is only theoretical is that nowhere in the current code base do we do tuplesort_set_bound() when performing a Datum sort. However, let's backpatch a fix for this as if any extension uses the code in this way then it's likely to cause problems. Author: Ronan Dunklau Discussion: https://postgr.es/m/CAApHDvpdoqNC5FjDb3KUTSMs5dg6f+XxH4Bg_dVcLi8UYAG3EQ@mail.gmail.com Backpatch-through: 9.6, oldest supported version
2021-07-10Fix assign_record_type_typmod().Jeff Davis
If an error occurred in the wrong place, it was possible to leave an unintialized entry in the hash table, leading to a crash. Fixed. Also, be more careful about the order of operations so that an allocation error doesn't leak memory in CacheMemoryContext or unnecessarily advance NextRecordTypmod. Backpatch through version 11. Earlier versions (prior to 35ea75632a5) do not exhibit the problem, because an uninitialized hash entry contains a valid empty list. Author: Sait Talha Nisanci <Sait.Nisanci@microsoft.com> Reviewed-by: Andres Freund Discussion: https://postgr.es/m/HE1PR8303MB009069D476225B9A9E194B8891779@HE1PR8303MB0090.EURPRD83.prod.outlook.com Backpatch-through: 11
2021-07-10Fix numeric_mul() overflow due to too many digits after decimal point.Dean Rasheed
This fixes an overflow error when using the numeric * operator if the result has more than 16383 digits after the decimal point by rounding the result. Overflow errors should only occur if the result has too many digits *before* the decimal point. Discussion: https://postgr.es/m/CAEZATCUmeFWCrq2dNzZpRj5+6LfN85jYiDoqm+ucSXhb9U2TbA@mail.gmail.com
2021-07-09Add missing Int64GetDatum macro in dbsize.cDavid Rowley
I accidentally missed adding this when adjusting 55fe60938 for back patching. This adjustment was made for 9.6 to 13. 14 and master are not affected. Discussion: https://postgr.es/m/CAApHDvp=twCsGAGQG=A=cqOaj4mpknPBW-EZB-sd+5ZS5gCTtA@mail.gmail.com
2021-07-09Fix incorrect return value in pg_size_pretty(bigint)David Rowley
Due to how pg_size_pretty(bigint) was implemented, it's possible that when given a negative number of bytes that the returning value would not match the equivalent positive return value when given the equivalent positive number of bytes. This was due to two separate issues. 1. The function used bit shifting to convert the number of bytes into larger units. The rounding performed by bit shifting is not the same as dividing. For example -3 >> 1 = -2, but -3 / 2 = -1. These two operations are only equivalent with positive numbers. 2. The half_rounded() macro rounded towards positive infinity. This meant that negative numbers rounded towards zero and positive numbers rounded away from zero. Here we fix #1 by dividing the values instead of bit shifting. We fix #2 by adjusting the half_rounded macro always to round away from zero. Additionally, adjust the pg_size_pretty(numeric) function to be more explicit that it's using division rather than bit shifting. A casual observer might have believed bit shifting was used due to a static function being named numeric_shift_right. However, that function was calculating the divisor from the number of bits and performed division. Here we make that more clear. This change is just cosmetic and does not affect the return value of the numeric version of the function. Here we also add a set of regression tests both versions of pg_size_pretty() which test the values directly before and after the function switches to the next unit. This bug was introduced in 8a1fab36a. Prior to that negative values were always displayed in bytes. Author: Dean Rasheed, David Rowley Discussion: https://postgr.es/m/CAEZATCXnNW4HsmZnxhfezR5FuiGgp+mkY4AzcL5eRGO4fuadWg@mail.gmail.com Backpatch-through: 9.6, where the bug was introduced.
2021-07-05Reduce overhead of cache-clobber testing in LookupOpclassInfo().Tom Lane
Commit 03ffc4d6d added logic to bypass all caching behavior in LookupOpclassInfo when CLOBBER_CACHE_ALWAYS is enabled. It doesn't look like I stopped to think much about what that would cost, but recent investigation shows that the cost is enormous: it roughly doubles the time needed for cache-clobber test runs. There does seem to be value in this behavior when trying to test the opclass-cache loading logic itself, but for other purposes the cost is excessive. Hence, let's back off to doing this only when debug_invalidate_system_caches_always is at least 3; or in older branches, when CLOBBER_CACHE_RECURSIVELY is defined. While here, clean up some other minor issues in LookupOpclassInfo. Re-order the code so we aren't left with broken cache entries (leading to later core dumps) in the unlikely case that we suffer OOM while trying to allocate space for a new entry. (That seems to be my oversight in 03ffc4d6d.) Also, in >= v13, stop allocating one array entry too many. That's evidently left over from sloppy reversion in 851b14b0c. Back-patch to all supported branches, mainly to reduce the runtime of cache-clobbering buildfarm animals. Discussion: https://postgr.es/m/1370856.1625428625@sss.pgh.pa.us
2021-06-24Another fix to relmapper race condition.Heikki Linnakangas
In previous commit, I missed that relmap_redo() was also not acquiring the RelationMappingLock. Thanks to Thomas Munro for pointing that out. Backpatch-through: 9.6, like previous commit. Discussion: https://www.postgresql.org/message-id/CA%2BhUKGLev%3DPpOSaL3WRZgOvgk217et%2BbxeJcRr4eR-NttP1F6Q%40mail.gmail.com
2021-06-24Prevent race condition while reading relmapper file.Heikki Linnakangas
Contrary to the comment here, POSIX does not guarantee atomicity of a read(), if another process calls write() concurrently. Or at least Linux does not. Add locking to load_relmap_file() to avoid the race condition. Fixes bug #17064. Thanks to Alexander Lakhin for the report and test case. Backpatch-through: 9.6, all supported versions. Discussion: https://www.postgresql.org/message-id/17064-bb0d7904ef72add3@postgresql.org
2021-06-18Don't set a fast default for anything but a plain tableAndrew Dunstan
The fast default code added in Release 11 omitted to check that the table a fast default was being added to was a plain table. Thus one could be added to a foreign table, which predicably blows up. Here we perform that check. In addition, on the back branches, since some of these might have escaped into the wild, if we encounter a missing value for an attribute of something other than a plain table we ignore it. Fixes bug #17056 Backpatch to release 11, Reviewed by: Andres Freund, Álvaro Herrera and Tom Lane
2021-06-12Ensure pg_filenode_relation(0, 0) returns NULL.Tom Lane
Previously, a zero value for the relfilenode resulted in a confusing error message about "unexpected duplicate". This function returns NULL for other invalid relfilenode values, so zero should be treated likewise. It's been like this all along, so back-patch to all supported branches. Justin Pryzby Discussion: https://postgr.es/m/20210612023324.GT16435@telsasoft.com
2021-06-01Reject SELECT ... GROUP BY GROUPING SETS (()) FOR UPDATE.Tom Lane
This case should be disallowed, just as FOR UPDATE with a plain GROUP BY is disallowed; FOR UPDATE only makes sense when each row of the query result can be identified with a single table row. However, we missed teaching CheckSelectLocking() to check groupingSets as well as groupClause, so that it would allow degenerate grouping sets. That resulted in a bad plan and a null-pointer dereference in the executor. Looking around for other instances of the same bug, the only one I found was in examine_simple_variable(). That'd just lead to silly estimates, but it should be fixed too. Per private report from Yaoguang Chen. Back-patch to all supported branches.
2021-05-29Fix race condition when sharing tuple descriptors.Thomas Munro
Parallel query processes that called BlessTupleDesc() for identical tuple descriptors at the same moment could crash. There was code to handle that rare case, but it dereferenced a bogus DSA pointer. Repair. Back-patch to 11, where commit cc5f8136 added support for sharing tuple descriptors in parallel queries. Reported-by: Eric Thinnes <e.thinnes@gmx.de> Discussion: https://postgr.es/m/99aaa2eb-e194-bf07-c29a-1a76b4f2bcf9%40gmx.de
2021-05-21Restore the portal-level snapshot after procedure COMMIT/ROLLBACK.Tom Lane
COMMIT/ROLLBACK necessarily destroys all snapshots within the session. The original implementation of intra-procedure transactions just cavalierly did that, ignoring the fact that this left us executing in a rather different environment than normal. In particular, it turns out that handling of toasted datums depends rather critically on there being an outer ActiveSnapshot: otherwise, when SPI or the core executor pop whatever snapshot they used and return, it's unsafe to dereference any toasted datums that may appear in the query result. It's possible to demonstrate "no known snapshots" and "missing chunk number N for toast value" errors as a result of this oversight. Historically this outer snapshot has been held by the Portal code, and that seems like a good plan to preserve. So add infrastructure to pquery.c to allow re-establishing the Portal-owned snapshot if it's not there anymore, and add enough bookkeeping support that we can tell whether it is or not. We can't, however, just re-establish the Portal snapshot as part of COMMIT/ROLLBACK. As in normal transaction start, acquiring the first snapshot should wait until after SET and LOCK commands. Hence, teach spi.c about doing this at the right time. (Note that this patch doesn't fix the problem for any PLs that try to run intra-procedure transactions without using SPI to execute SQL commands.) This makes SPI's no_snapshots parameter rather a misnomer, so in HEAD, rename that to allow_nonatomic. replication/logical/worker.c also needs some fixes, because it wasn't careful to hold a snapshot open around AFTER trigger execution. That code doesn't use a Portal, which I suspect someday we're gonna have to fix. But for now, just rearrange the order of operations. This includes back-patching the recent addition of finish_estate() to centralize the cleanup logic there. This also back-patches commit 2ecfeda3e into v13, to improve the test coverage for worker.c (it was that test that exposed that worker.c's snapshot management is wrong). Per bug #15990 from Andreas Wicht. Back-patch to v11 where intra-procedure COMMIT was added. Discussion: https://postgr.es/m/15990-eee2ac466b11293d@postgresql.org
2021-05-10Prevent integer overflows in array subscripting calculations.Tom Lane
While we were (mostly) careful about ensuring that the dimensions of arrays aren't large enough to cause integer overflow, the lower bound values were generally not checked. This allows situations where lower_bound + dimension overflows an integer. It seems that that's harmless so far as array reading is concerned, except that array elements with subscripts notionally exceeding INT_MAX are inaccessible. However, it confuses various array-assignment logic, resulting in a potential for memory stomps. Fix by adding checks that array lower bounds aren't large enough to cause lower_bound + dimension to overflow. (Note: this results in disallowing cases where the last subscript position would be exactly INT_MAX. In principle we could probably allow that, but there's a lot of code that computes lower_bound + dimension and would need adjustment. It seems doubtful that it's worth the trouble/risk to allow it.) Somewhat independently of that, array_set_element() was careless about possible overflow when checking the subscript of a fixed-length array, creating a different route to memory stomps. Fix that too. Security: CVE-2021-32027